Featured Research

from universities, journals, and other organizations

Beetle-inspired Switch Uses Water For Bonding

Date:
August 27, 2005
Source:
Cornell University News Service
Summary:
A new switch designed by Cornell University engineers uses water droplets to create very strong adhesive bonds that can flicked on and off in an instant. The switch was inspired by a mechanism found in palm beetles and is described in the Proceedings of the National Academy of Sciences (Vol. 102 (34) 11974-11979, 2005).

The droplet switch shown here toggles between a big droplet positioned above and below the plate using applied voltage. This novel electro-mechanical switch is capable of working by itself or in larger arrays, and has fast switching times with low voltages, no moving solid parts and can be made very small. Applications are envisioned in the areas of mechanics, micro-fluidics and optics, among others. (Vogel/Steen, copyright PNAS)

ITHACA, N.Y. -- Imagine this: A tiny, fast switch that useswater droplets to create adhesive bonds almost as strong as aluminum byborrowing a mechanism found in palm beetles.

The newbeetle-inspired switch, designed by Cornell University engineers, canwork by itself on the scale of a micron -- a millionth of a meter. Theswitches can be combined in arrays for larger applications likepowerful adhesive bonding. Like the transistor, whose varied usesbecame apparent only following its invention, the uses of the newswitch are not yet understood. But the switch's simplicity, smallnessand speed have enormous potential, according to the researchers.

"Almostall the greatest technological advances have depended on switches, andthis is a switch that is fast and can be scaled down," said Paul Steen,a professor of chemical and biomolecular engineering at Cornell andco-author of a paper published in the Proceedings of the NationalAcademy of Sciences (Vol. 102, No. 34).

Steen dreamed up the ideaof the switch after listening to Cornell entomologist Tom Eisnerlecture on palm beetles, which are native to the southeastern UnitedStates.
Like the beetle, which clings to a palm leaf at adhesivestrengths equal to a hundred times its own body weight -- the humanequivalent of carrying seven cars -- the switch in its most basic formuses surface tension created by water droplets in contact with asurface, in much the same way as two pieces of wet paper cling together.

Whenattacked, the palm beetle attaches itself to a leaf until the attackerleaves. It adheres with 120,000 droplets of secreted oil, each making abridgelike contact between the beetle's feet and the leaf. Each dropletis just a few microns wide. Whereas the beetle controls the oilcontacts mechanically, Steen's switch uses water and electricity.

Forthe switch to make or release a bond created by surface tension, awater droplet moves to the top or bottom of a flat plate surface usingelectricity from electrodes. The electricity moves positively chargedatoms, called ions, in the water through the minute capillaries of athin disk of porous glass embedded in the plate. The water moves andwells up into a micrometer-sized droplet on the plate surface. Theexposed droplet can then stick to another surface. To break the bond,electricity pulls the exposed water back through the capillary pores.

Withmillimeter-sized water droplets and micron-sized pores, 5 volts canturn the switch on in one second. At the same time, the researcherspredict that smaller droplets will require less energy to move and havefaster switching times. Steen and his colleagues believe that a switchas small as hundreds of nanometers, close to a billionth of a meter andone-tenth the size of the beetle droplets, is within reach. Researcherscould also create large effects from many tiny switches by connectingthem in various arrangements, Steen said.

"This new technologybridges the gap between scales as large as our hands and nanoscales,"said Steen. "We need devices that allow us to communicate between thetwo scales."

Co-authors include Michael Vogel, a postdoctoralresearcher in Cornell's Department of Chemical and BiomolecularEngineering, and researcher Peter Ehrhard at the Institute for Nuclearand Energy Technologies in Karlsruhe, Germany. Since much of this workwas conducted while the three scientists were at the German institute,the patent application was filed in Germany.

The study wassupported by NASA, the National Science Foundation, theForschungszentrum Karlsruhe and the Deutscher Akademischer AustauschDienst.


Story Source:

The above story is based on materials provided by Cornell University News Service. Note: Materials may be edited for content and length.


Cite This Page:

Cornell University News Service. "Beetle-inspired Switch Uses Water For Bonding." ScienceDaily. ScienceDaily, 27 August 2005. <www.sciencedaily.com/releases/2005/08/050823081552.htm>.
Cornell University News Service. (2005, August 27). Beetle-inspired Switch Uses Water For Bonding. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2005/08/050823081552.htm
Cornell University News Service. "Beetle-inspired Switch Uses Water For Bonding." ScienceDaily. www.sciencedaily.com/releases/2005/08/050823081552.htm (accessed July 25, 2014).

Share This




More Matter & Energy News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
TSA Administrator on Politics and Flight Bans

TSA Administrator on Politics and Flight Bans

AP (July 24, 2014) TSA administrator, John Pistole's took part in the Aspen Security Forum 2014, where he answered questions on lifting of the ban on flights into Israel's Tel Aviv airport and whether politics played a role in lifting the ban. (July 24) Video provided by AP
Powered by NewsLook.com
Creative Makeovers for Ugly Cellphone Towers

Creative Makeovers for Ugly Cellphone Towers

AP (July 24, 2014) Mobile phone companies and communities across the country are going to new lengths to disguise those unsightly cellphone towers. From a church bell tower to a flagpole, even a pencil, some towers are trying to make a point. (July 24) Video provided by AP
Powered by NewsLook.com
Algonquin Power Goes Activist on Its Target Gas Natural

Algonquin Power Goes Activist on Its Target Gas Natural

TheStreet (July 23, 2014) When The Deal's Amanda Levin exclusively reported that Gas Natural had been talking to potential suitors, the Ohio company responded with a flat denial, claiming its board had not talked to anyone about a possible sale. Lo and behold, Canadian utility Algonquin Power and Utilities not only had approached the company, but it did it three times. Its last offer was for $13 per share as Gas Natural's was trading at a 60-day moving average of about $12.50 per share. Now Algonquin, which has a 4.9% stake in Gas Natural, has taken its case to shareholders, calling on them to back its proposals or, possibly, a change in the target's board. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins